1. Field of the Invention
The present invention relates to the field of imaging through the use of radiant pulse-echo energy or ultrasound technology. More particularly, the present invention relates to a multi-dimensional transducer array which can be selectively operated in either a two-dimensional (2D) scan mode or three-dimensional (3D) scan mode.
2. Art Background
Generally, most transducer probes operate in accordance with essentially the same principle, wherein a burst or pulse of energy is introduced into the object being examined, and a return echo is received, from which an image is generated. In order to allow for different dimensional views or perspectives of a particular object/area, however, a multitude of different devices have been developed.
Currently, imaging devices are capable of providing two-dimensional (2D) or three-dimensional (3D) views of objects/areas through the use of radiant pulse-echo energy or ultrasound technology. Typical ultrasound devices, however, utilize a series of different transducer arrays contained in a variety of different probe tips which are specifically designed to obtain either a two-dimensional (2D) or three-dimensional (3D) image of a particular area of interest.
Generally, a one-dimensional transducer array configuration is utilized for obtaining a two-dimensional (2D) image of a particular object or area of interest. Specifically, a one-dimensional transducer array is utilized to obtain a two-dimensional (2D) view or image (lateral and axial), which represents a cross-section of the object or area, through a corresponding scanning plane along the X and Z axes. The one-dimensional transducer array, also known as a linear array, comprises an array of rectangular transducer elements arranged into columns which form a single-dimensional linear array. Generally, two-dimensional (2D) imaging systems use electronic scanning of a linear, curved linear, or phased array type, which typically employ 64-192 transducer elements within the probe. Accordingly, the single-dimensional linear array typically provides a relatively high quality two-dimensional (2D) profile or image of the particular area of interest.
One method of obtaining a three-dimensional (3D) view or image is accomplished by the mechanical movement of the transducer array contained in the probe (electronic/mechanical probe). The electronic/mechanical probe obtains 3D imaging by the movement of a one-dimensional array (2D imaging) about the area of interest, resulting in a third scanning dimension to provide a three-dimensional (3D) view or image. An advantage of the electronic/mechanical probe is that it can be used for conventional two-dimensional (2D) imaging by simply stopping the mechanical movement of the probe into a fixed position.
Another method for obtaining a three-dimensional (3D) view or image of an object is through electronic volume scanning. Electronic volume scanning requires a two-dimensional transducer array which is utilized to obtain a three-dimensional (3D) view or image of a particular area of interest. The two-dimensional transducer array obtains a three-dimensional (3D) view or image (lateral, axial, and elevational), which represents a cross-section of the object, through a corresponding scanning plane along the X, Y, and Z axes.
The two-dimensional transducer array typically comprises a plurality of transducer elements which are arranged into a two-dimensional configuration of columns and rows, as opposed to the one-dimensional transducer array configuration of columns used in two-dimensional (2D) scanning. The columns of the two-dimensional transducer array comprise the scanning plane used to form a two-dimensional profile of the object, and the rows of the array comprise the elevational plane used for obtaining the third dimension of the object. The probe used for electronic volume scanning, however, typically requires 2000 or more elements in order to obtain a relatively high quality full electronic volume scan. Nevertheless, this type of probe is often preferable to the electronic/mechanical probe, since the volume scan probe has a potential for relatively higher volume scan rates, due in part to the lack of mechanical movement.
For reasons of economy, based upon such considerations as the number of cables, the complexity of necessary electronic support circuitry, and associated beamformer considerations, typical three-dimensional (3D) scanning is typically implemented by using various forms of sparse array configurations. Generally, sparse array configurations utilize a limited set of transducer elements from the full two-dimensional arrangement of elements of the two-dimensional array. A typical sparse array configuration could contain between 256 and 512 transducer elements which would be utilized for three-dimensional (3D) scanning. The arrangement of the transducer elements in a sparse array can be in various formats, such as, randomly selected, randomly selected within the constraints of a binned pattern, periodic patterns with different periodicity for the transmitter and receiver elements, algorithmically optimized patterns from computer optimization, or a combination of periodic and algorithmically optimized patterns. Nevertheless, the sparse array or set of elements will generally provide a reduced image quality which may be sufficient for three-dimensional (3D) imaging. However, if a two-dimensional (2D) scan is preferred utilizing such array formats, the image quality will generally be inferior to that of a state of the art two-dimensional (2D) scanner.
To obtain two-dimensional (2D) images, all of the 2000 or more elements of the two-dimensional array must be used. The use of all 2000 or more of the elements of the two-dimensional array, however, would require a large multitude of cables and channels along with increased electronic support circuits, which would greatly increase the size, complication, and the expense of such a probe using a two-dimensional array for two-dimensional (2D) scanning. Thus, in actual practice, two separate transducer probes are typically utilized in order to provide quality imaging in variant dimensions, for example, a one-dimensional array for two-dimensional (2D) images, and a two-dimensional transducer array for three-dimensional (3D) images.
Thus, prior transducers for ultrasonic imaging have fundamental shortcomings in providing a singular probe which has the capability to provide both two-dimensional (2D) or three-dimensional (3D) images of high quality within the confines of a singular transducer probe. Therefore, it would be desirable to have an imaging device which could provide relatively high quality two-dimensional (2D) or three-dimensional (3D) images of objects within a singular transducer array contained in a singular probe.